This invention relates to a universal microscope condenser having a fixed lens member, two lens members that can alternately be switched on and off to vary the aperture and luminous field, and a variable aperture stop in the space between the switchable lenses.
This type of condenser is exemplified in German Offenlegungsschrift No. 2,116,625 in which the switchable lens members are connected via a common bevel gear and in which the lens members move in parallel planes after rectification.